[H3tren]3+ and [H4tren]4+ fluoride zirconates or tantalates

Four new [H3tren]3+ or [H4tren]4+ fluoride zirconates and two new [H3tren]3+ fluoride tantalates are evidenced in the (ZrF4 or Ta2O5)-tren-HFaq.-ethanol systems at 190 °C: the structurally related phases [H4tren]·(Zr2F12)·H2O and α-[H4tren]·(Zr2F12) (P212121), β-[H4tren]·(Zr2F12) (P21/c), [H3tren]4·(ZrF8)3·4H2O (I23), β-[H3tren]2·(Ta3O2F16)·(F) (R32) and its monoclinic distortion α-[H3tren]2·(Ta3O2F16)·(F) (C2/m). α and β-[H4tren]·(Zr2F12) and [H4tren]·(Zr2F12)·H2O are built up from (Zr2F12) dimers of edge sharing ZrF7 polyhedra while isolated ZrF8 dodecahedra are found in [H3tren]4·(ZrF8)3·4H2O. Linear (Ta3O2F16) trimers build α and β-[H3tren]2·(Ta3O2F16)·(F); they consist of two (TaOF6) pentagonal bipyramids that are linked to two opposite oxygen atoms of one central (TaO2F4) octahedron. A disorder affects the equatorial fluorine atoms of the trimers and eventually carbon or nitrogen atoms of [H3tren]3+ cations.

Six new [H3tren]3+ and [H4tren]4+ fluoride zirconates or tantalates are evidenced in the (ZrF4 or Ta2O5)-tren-HFaq.-ethanol systems at 190 °C in solvothermal conditions.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis in solvothermal conditions of [H3tren]3+ and [H4tren]4+ ZrIV or TaV fluorides.
► Structures based on ZrF8 monomers, Zr2F12 dimers and Ta3O2F16 trimers.
► α and β allotropic varieties of [H4tren]·(Zr2F12) and [H3tren]2·(Ta3O2F16)·(F).